ECB action 'couple of months' away: Ex-board member

European Central Bank (ECB) President Mario Draghi is preparing the way for monetary easing, a former member of the central bank told CNBC on Friday, despite some dismay after the ECB's failure to act this week.

The ECB opted to hold its key interest rate at 0.25 percent on Thursday, as well as keep the rate on its deposit facility at zero. This was despite calls from the likes of the International Monetary Fund's Christine Lagarde for action to combat disinflation, after euro zone inflation slipped to a 52-month low of 0.5 percent in March.

Lorenzo Bini Smaghi, an ex-member of the ECB executive board, forecast easing was coming, and said the delay was due to attempts by Draghi to build unanimity for action among the Governing Council's 24 members.

"I think he is gaining time for the argument to be won within the council," Bini Smaghi told CNBC on Friday, from the Ambrosetti Forum in Italy.

"The ECB is a bit different as a central bank; it needs to create a consensus, because a move by the ECB with a consensus is more credible than a move with a divided council. I think he needs the decision to mature within the Governing Council."

Despite the inaction, Draghi emphasized in his news conference on Thursday that the ECB could act swiftly to instigate "unconventional" policy measures if necessary. He also flagged that both quantitative easing and negative deposit rates had been discussed at this week's meeting.

Bini Smaghi predicted that easing would materialize in "a couple of months".

"I think he is preparing the markets to understand that action will take place," Bini Smaghi said.

"Inflation is low; the exchange rate is high. So the time for action should be coming soon… Especially for debt reduction, for the deleveraging process, low inflation is really bad."

"The ECB clearly signaled that it is prepared to utilize unconventional monetary policy easing," Hardman said in a research note on Friday.

He added: "The increased likelihood of the ECB adopting more effective monetary easing measures ahead, which could lift inflation expectations and lower real yields, have increased downside risks for the euro."

"While the ECB arguably remains excessively timid, we continue to expect policy to remain unchanged over coming quarters," said Grant Lewis, Daiwa Capital Market's head of research, in a note.

"We continue to see QE (quantitative easing), incorporating government bond purchases, as very much a last resort. Indeed, Draghi argued that a Federal Reserve/Bank of England/Bank of Japan-style program, based on government bond purchases, was less suitable for the euro area's bank-centric financial system."

Even if the ECB did act, it is uncertain what shape easing might take.

"The ECB remains undecided over the exact form of QE, which creates uncertainty over the potential size of asset purchases," said Hardman.